Wood burning stove

ABSTRACT

A stove having a drying chamber and a combustion chamber wherein fuel is dried in the drying chamber before being burned in the combustion chamber. In one embodiment, the drying chamber is located above the combustion chamber so that after the fuel is dried in the drying chamber it can be dropped into the combustion chamber for combustion.

BACKGROUND OF THE INVENTION

Fireplaces and stoves have been used for centuries to heat houses and other structures. Due in part to the high prices of oil and natural gas, fireplaces and stoves have recently become more cost effective and more desirable than ever before. Stoves generally comprise a combustion chamber in which fuel (usually wood) is burned to produce heat energy. The heat energy is transferred from the combustion chamber into heat ducts which carry the heat to the structure to be heated. Smoke and other exhaust gases are vented outside through exhaust ducts.

Although many existing wood burning stoves are effective for heating structures, many of them also contain inefficiencies. One problem with many prior art stoves is that they must be taken offline (i.e. the fire must be extinguished) in order to do maintenance or repairs on the stove. This is inefficient and costly since an alternate heat source must be employed during the maintenance/repairs to the wood stove. Another problem with many prior art stoves is that the composition of the fuel source (usually wood) is not consistent. The kind of wood as well as the wood's moisture content can affect the amount of heat produced by the stove. For example, wood having a high moisture content usually transfers less heat energy to the structure to be heated. In order to overcome this problem, many prior art stoves (such as U.S. Pat. No. 5,873,356 to Vossler) use wood that has been cut into small pieces called “pellets.” The small size of the pellets helps the wood dry more quickly thereby increasing the heat energy of the combustion and reducing the energy used to dry the wood. The problem with cutting wood into pellets is that it requires a significant amount of time and expense. Often, the pellets must be purchased commercially which is a considerable disadvantage for a homeowner that wants to burn wood that has been cut from his/her own property.

There is therefore a need for a wood burning stove that efficiently uses heat to dry the wood before it is introduced into the combustion chamber. There if further a need for a wood burning stove that is able to remain online during maintenance and repair procedures.

SUMMARY OF THE INVENTION

The present invention comprises a wood burning stove having a drying chamber and a combustion chamber. A fuel (such as wood) is dried in the drying chamber before entering the combustion chamber where the fuel is burned. The drying chamber is in communication with the combustion chamber so that heat from the combustion chamber transfers into the drying chamber thereby causing the fuel in the drying chamber to dry allowing it to burn more efficiently when it enters the combustion chamber.

In one embodiment, the drying chamber is located above the combustion chamber. The drying chamber has a floor or other suitable support means to hold the fuel above the combustion chamber. The drying chamber support means comprises an opening to allow heat from the combustion chamber to enter the drying chamber. The drying chamber comprises at least one movable member having a first position and a second position. In some embodiments, the support means is the movable member. In the first position, the movable member retains the fuel in the drying chamber. In the second position the movable member allows the fuel in the drying chamber to fall into the combustion chamber. In use, when the fuel in the drying chamber has dried, the movable member is moved from its first position to its section position to allow the fuel to fall into the combustion chamber.

The stove further comprises a housing in which the drying and combustion chambers are located. In one embodiment, the drying and combustion chambers are removable from the stove housing during operation of the stove. The removability of the drying chamber allows a batch of fuel to continually be in the process of drying in the stove. In other words, more than one drying chamber may be used so that as one batch of fuel is drying inside the stove, another batch of fuel can be loaded onto a second drying chamber. The second drying chamber can be exchanged with the first drying chamber after the first drying chamber deposits its dried fuel into the combustion chamber thereby reducing the amount of time that a drying chamber is not in the stove.

The present invention is advantageous over prior art stoves because the wood is dried by the stove before it is introduced into the combustion chamber. This eliminates the need to chop the wood into small pieces before it is introduced into the combustion chamber. The removability of the chambers provides a stove that remains online even when the chambers require maintenance or are being loaded with additional fuel.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of an embodiment of the stove showing heat ducts for transporting heat from the stove to a structure being heated;

FIG. 2 is side view of an embodiment of the stove showing the chambers removed from the stove's housing;

FIG. 3 is a side view of an embodiment of the stove showing it in operation with the chambers inside the housing; and

FIG. 4 is a side view of an embodiment of the drying chamber showing the movable members in their open position.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

The present invention comprises a stove 15 having at least two chambers 10, 12 wherein fuel 16 is dried in a drying chamber 10 before entering the combustion chamber 12 where the fuel 16 is burned. FIG. 1 shows the stove 15 in operation wherein heat energy is being produced in the combustion chamber 12 and then transferred from the stove 15 into heat ducts 22 which carry and expel hot air into the structure 24 to be heated. Examples of fuels 16 that can be burned in the stove 15 include cull logs and wooden creates, however, it should be noted that any suitable fuel 16 may be used.

Further, it should be noted that in some embodiments the chambers 10, 12 are adapted to receive logs (fuel 16) that are about fourteen feet in length. This large chamber 10, 12 size allows the stove 15 to burn fuel 16 such as large crates, trees, and fence posts without having to cut or dismantle them. This is particularly advantageous when the fuel 16 has nails or other metal objects that would damage equipment that attempted to cut the fuel 16 into smaller pieces.

The drying chamber 10 is in communication with the combustion chamber 12 so that heat from the combustion chamber 12 transfers into the drying chamber 10 thereby causing the fuel 16 in the drying chamber 10 to dry allowing it to burn more efficiently when it enters the combustion chamber 10. FIGS. 1-3 show an embodiment of the invention wherein the drying chamber 10 is located above the combustion chamber 12. In this embodiment, the drying chamber 10 has a floor or wall with openings therein to allow heat from the combustion chamber 12 to enter the drying chamber 10 to dry out the fuel 16. As seen in FIG. 1, the heat ducts 22 and exhaust ducts 23 are located above the drying chamber 10. The arrangement of the heat ducts 22 and exhaust ducts 23 above the drying chamber 10 allows the heat and exhaust gases to pass through the drying chamber 10 after its formation in the combustion chamber 12 to aid in drying the fuel 16. In this embodiment (wherein the drying chamber 10 is located above the combustion chamber 12) the majority of combustion occurs in the combustion chamber 12. However, because of the positioning of the drying chamber 10 above the combustion chamber 12, some combustion may also occur in the drying chamber 10.

In one embodiment, the stove 15 comprises at least one movable member 18 adapted to be movable between a first position and a second position by an actuating member 20. In the embodiment shown in FIGS. 3 and 4, the movable member 18 comprises the floor of the drying chamber 10. The movable member 18 comprises two opposed movable members 20. FIG. 3 shows the movable members in the first (closed) position while FIG. 4 shows the movable members 18 in the second (open) position. In the first position, the movable member(s) 18 retains the fuel 16 in the drying chamber 10. In the second position the movable member(s) 18 allows the fuel 16 in the drying chamber 10 to fall into the combustion chamber 12. In use, when the fuel 16 in the drying chamber 10 has dried, the movable member 18 is moved from its first position to its section position by actuating member 20 to allow the dried fuel 16 to fall into the combustion chamber 12. Actuating member 20 may be any suitable actuator including a hydraulic actuating means, an electric actuating means, a pneumatic actuating means, or a manual actuating means.

As shown best in FIG. 2, the stove further comprises a housing 11 in which the drying 10 and combustion chambers 12 are located. In the embodiment shown in FIG. 2, the drying 10 and combustion chambers 12 are detachable from the stove 15 housing 11 during operation of the stove 15. In one embodiment, the chambers 10, 12 have flanges along their edges that slide on and are supported by rails extending inwardly from the inside of the housing 11. In some embodiments, the flanges or rails may comprise bearings or wheels that allow the flange to slide more easily over the rails. The removability of the drying chamber 10 allows a batch of fuel 16 to continually be drying in the stove. In other words, more than one drying chamber 10 may be used so that as one batch of fuel 16 is drying inside the stove, another batch of fuel 16 can be loaded into another drying chamber 10. The second drying chamber 10 can be exchanged with the first drying chamber 10 after the first drying chamber 10 deposits its dried fuel 16 into the combustion chamber 12 thereby reducing the amount of time that a drying chamber 10 is not in the stove 15. In this manner, the stove is continually combusting fuel in the combustion chamber 12 and continually drying wood in the drying chamber 10. The removability of the combustion chamber 12 also allows the user to insert a backup combustion chamber 12 into the stove in the event the primary combustion chamber 12 requires maintenance.

As seen in FIGS. 2 and 3, in one embodiment the stove comprises an ash chamber 14 below the combustion chamber 12 to receive ash from the combustion. The combustion chamber 12 preferably has openings in its floor to allow ash from combustion to fall into the third chamber 14 which helps keep the combustion chamber 12 clean and free of non-combustible material. As shown in FIG. 2, the ash chamber 14 may also be removable from the housing 11 to allow the ash to be disposed of without having to stop the operation of the stove.

Having thus described the invention in connection with the preferred embodiments thereof, it will be evident to those skilled in the art that various revisions can be made to the preferred embodiments described herein with out departing from the spirit and scope of the invention. It is my intention, however, that all such revisions and modifications that are evident to those skilled in the art will be included with in the scope of the following claims. 

1. A stove for burning fuel to produce heat, said stove comprising: a housing; a combustion chamber removably combined with the housing and adapted to receive and burn fuel therein; a drying chamber removably combined with the housing wherein the drying chamber is in communication with the combustion chamber so that heat from the combustion chamber is transferred into the drying chamber to dry the fuel in the drying chamber before it is burned in the combustion chamber.
 2. A stove for burning fuel to produce heat, said stove comprising: a housing; a combustion chamber combined with the housing and adapted to receive and burn fuel therein; a drying chamber combined with the housing above the combustion chamber wherein the drying chamber is in communication with the combustion chamber so that heat from the combustion chamber is transferred upward into the drying chamber to dry the fuel in the drying chamber before it is burned in the combustion chamber; wherein the drying chamber comprises a movable member adapted to move from a first position wherein the fuel is held in the drying chamber to a second position wherein the fuel is dropped from the drying chamber into the combustion chamber.
 3. The stove of claim 2 wherein the fuel is wood.
 4. The stove of claim 2 wherein the movable member is moved from the first position to the second position by an actuator.
 5. The stove of claim 2 wherein the drying chamber is removable from the housing.
 6. The stove of claim 2 wherein the combustion chamber is removable from the housing.
 7. The stove of claim 2 further comprising an ash chamber combined with the housing below the combustion chamber and adapted to receive ash from the combustion chamber.
 8. The stove of claim 7 wherein the ash chamber is removable from the housing.
 9. A stove for burning fuel to produce heat, said stove comprising: a housing; a combustion chamber combined with the housing and adapted to receive and burn fuel therein; a drying chamber combined with the housing above the combustion chamber wherein the drying chamber is in communication with the combustion chamber so that heat from the combustion chamber is transferred upward into the drying chamber to dry the fuel in the drying chamber before it is burned in the combustion chamber; and a exhaust duct for carrying exhaust away from the stove wherein the exhaust duct is located above the drying chamber so the heated exhaust must travel from the combustion chamber through the drying chamber and into the exhaust duct which carries the heated exhaust away from the stove. 